US Patent:
20080012594, Jan 17, 2008
Inventors:
Shaoning Lu - Monrovia CA, US
Melvin Khoo - San Gabriel CA, US
Nim Tea - Orange CA, US
International Classification:
G01R 31/02
Abstract:
A novel method and structure for counter-balancing a lateral force exerted by a probe card onto a device under test (“DUT”) is disclosed. Many DUTs (particularly memory devices) are tested in parallel (i.e., many die at a time) and have unequal numbers of contact pads on top vs. bottom and/or right vs. left sides of the die. The probe card used to test the DUT would necessarily have an uneven distribution of probes that match the contact pads and, as a consequence, may exert a net lateral force on the DUT. By manipulating the individual characteristics of the individual probes, a probe card may be constructed that zeroes the lateral force. Characteristics such as the direction and stiffness of the individual probes can be varied to zero the net lateral force.